The present invention is directed to a contact arrangement for a high breaking capacity relay wherein a movable contact spring is moved between a pair of cooperating contact elements to form a transfer arrangement. Highly conductive contact members are secured to a free end of the contact spring and are immediately connected to a lead of the current system.
Large conductor cross-sections of material having good electrical conductivity are required for switching high currents, for example, in motor vehicle relays in order to keep the voltage drop and the heating low. Since movable contact springs in such relays often do not meet these demands due to their materials and due to their relatively small cross-section, a transition has already been made for conducting the current from one terminal element directly to the contact location by a stranded copper conductor with the stranded copper conductor being directly connected to a contact member.
The contact arrangement of this type is initially described and disclosed, for example, in German Gebrauchsmuster No. 81 09 089. As disclosed, a contact member on a contact spring of a relay is conducted rivet-like in a passage through the material of the contact spring and is connected directly to the flexible cable or lead on the opposite surface.
A similar contact arrangement is disclosed in German Patent No. 29 27 879. In this arrangement, a flexible cord or lead is conducted through a passage of a contact spring and is fashioned into the contact member itself at its end. In both instances, however, the contact arrangement is only involved with one cooperating contact element so that only a normally opened or respectively normally closed relay can be formed. Since given these designs, the lead is respectively approached to that side of the contact spring lying opposite the contact member, there is no room for a second contact member which would be required for a changeover contact or for a transfer contact arrangement. Therefore, if a changeover contact having two contact members lying opposire one another on the contact spring were required for the contact arrangement, the lead must be welded onto the contact spring itself up to the present time. If one did not wish to accept high resistance in the circuit, this means that the contact spring must be manufactured of an expensive material, for example, a copper alloy having spring properties.